Several
years after the founding of the Sangha
of monks (bhikkhu) the Buddha also established
the Sangha of nuns (bhikkhuni). His aunt Maha Pajapati
Gotami came to him requesting to be ordained, a request
that he initially turned down. However, on being reminded
by Ananda that women as well as men can attain Nirvana
he finally relented, but with several provisions:

These
were (1) in matters of deference and respect monks would
always have precedence over nuns; (2) nuns must spend
the yearly retreat in a place separate from monks; (3)
nuns must consult monks about certain monastic procedures
and about teaching the Dhamma;
(4) when a nun does wrong she must confess it before the
community of both monks and nuns; (5) a nun who breaks
an important Vinaya rule must undergo punishment before both monks
and nuns; (6) a nun must be ordained before an assembly
of both monks and nuns; (7) a nun must not revile or abuse
a monk and (8) a nun must not teach a monk. Gotami accepted
these extra rules and nuns became an integral part of
the Buddhist movement.